Galaxy J7 won’t connect to network after turning off Airplane Mode

Hello and welcome to today’s #GalaxyJ7 troubleshooting article. This post answers three issues for this device so be sure to browse through all of them. Like in previous posts, all the cases included below are first hand reports of users and some of them have already tried to troubleshoot the issue before contacting us. If you have a similar issue with one of the cases mentioned, don’t forget to also check the problem description so you’ll know what troubleshooting steps we skip.

Problem #1: Galaxy J7 won’t connect to network after turning off Airplane Mode

Hi there,.  I purchased a new Samsung J7 (unlocked), and used it with my AT&T sim for a few weeks. It worked fine until I switched on the Airplane mode for a one hour flight.  After switching the Airplane mode off, the phone stopped connecting to the AT&T network. AT&T gave me a new SIM card, but that didn’t solve the problem. They then re-configured the APN info, and that did not work.  I performed a factory reset and that did not fix the problem. I looked at the info on your site, but that did not seem to fix the problem either. Any other ideas? Thanks.

Solution: We’re not aware of any bug with Samsung’s Airplane mode blocking cellular connections. Toggling that mode may have triggered another bug which in turn caused the device to lose cellular connectivity. Whatever the cause is, that’s obviously secondary to the main issue, which is of course to bring back network connectivity. Since we don’t know the full history of the device, there’s no way we’ll be able to tell you what to do exactly. You need to narrow things down to hopefully fix the issue on your level. These are the few things that you can do:

Make sure SIM card is properly inserted

A Galaxy J7 SIM card tray may sometimes bend a little or break. Reinsert the SIM card correctly into the tray and push it down. This ensures that the metal connector of the card comes in contact with the metal pins in the tray. Then, turn the phone on and see what happens.

Install carrier updates

If applicable, try checking under Settings > Software update to see if there is an available update. Some network issues are fixed by installing code patches only. If you’re lucky and an update is necessary, downloading and installing it may be an easy fix.

Verify unlock status

You mentioned the phone is unlocked. This can mean two things — either (a) it was originally built for a different carrier (not for AT&T), or it’s originally from AT&T and was unlocked so it can be used in other networks. If the device is not AT&T branded, which means it was originally built for another company, there’s a chance that somehow, the network unlock modification was lost. We can’t say if that’s due to toggling Airplane Mode on and off but if it’s the only different thing that you did, then it must be the triggering mechanism. If the phone has lost is unlocked key, you need to unlock it again. This can mean bringing the phone back to where the place you bought it from, or letting the original company to which it was built to work with do the unlocking process. If you can’t do both, try to bring the phone to an independent shop and see if they can unlock it for you.

Work with network operator

If your Galaxy J7 is originally built for AT&T, you should continue working with them so they can figure out why the device has lost cellular connectivity.

Problem #2: How to fix Galaxy J7 battery drain issue: battery acting up and not showing correct percentage

I have had the phone since November 2016 and have never had water issues, dropping/crack issues, etc. Very clean phone. As the phone gets older battery life has diminished, but to be expected and manageable. However in the last couple weeks I have noticed that I’ll have the phone plugged into the fast charger overnight, wake up, unplug the phone and it says 97%. In other instances, I’ll have the phone on a charger and yet the % charge is not increasing or takes very long to charge. I had the phone in medium power saving mode this weekend and the batter was still dying fast. Even after I rebooted the phone. A couple months ago, I’d plug my phone into a non-fast charger at work with about 70% charge and within 20 minutes the phone said it was at 100%. It’s almost as if the phone is not correctly displaying the current battery life %.

I’m not excited about the thought of doing a factory reset because I’m afraid I’ll lose something even if I try to back everything up. I’m also not interested in backing up everything to a cloud. Thoughts, ideas? Has Samsung pulled an Apple and sent an update that’s making my battery life haywire? I just got done paying for this phone a month ago (after 2.5 years, 30 months).

Solution: Lithium-based batteries can start losing significant battery capacity after a year of daily use. If you’ve already tried all the tricks in the book on how to minimize battery drain (Google can help), then that’s probably because your phone’s battery has simply reached its twilight. Try to recalibrate it and see if it helps. Sometimes, Android simply loses accuracy in getting correct battery levels after continued use. By calibrating the battery, you may be able help the operating system receive actual battery capacity and levels. Here’s what you can do:

  1. Drain the battery completely. This means using your device until it powers down by its own and the battery level reads 0%.
  2. Charge the phone until it reaches 100%. Be sure to use original charging equipment for your device and let it charge up completely. Do not unplug your device for at least two more hours and also don’t use it while charging.
  3. After the elapsed time, unplug your device.
  4. Restart the device.
  5. Use your phone until it completely runs out of power again.
  6. Repeat steps 1-5.

Factory reset follows battery recalibration. If nothing changes after doing both, then it’s high time that you replace the battery.

Problem #3: How to fix a broken Galaxy J7 screen

Hello. My son owns a Galaxy J7 mobile phone. a few months ago we had to get a replacement screen fitted, as he dropped it and the screen shattered, it was working fine until 2 weeks ago as we went on holiday, he noticed a green line in the bottom left corner of the screen the next day there was purple dots all over the bottom third or so of the screen which later turned black, the next day the blackness had spread higher up the screen until eventually the whole screen was black, the phone still charges ok judging by the charging light, he says it has not gotten wet so could it be the screen again? 

Solution: Unfortunately, the signs you mentioned are classic symptoms of a broken screen, particularly the monitor or LCD. The replacement screen may be substandard or something may have damaged it again. Screen problem like this one can’t be fixed by doing a software solution so the best course of action for you is to bring the phone back to the shop that fitted the screen and let them fix it again.

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Harvey is keen with mobile technology and loves writing about all things mobile. He is passionate in helping technology-challenged people by finding resolution to their issues.

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